環境保護已是世界各先進國家普遍重視的課題，企業在面臨政府監督、社會的壓力以及國際競爭的情況下，不得不積極從事環境保護工作，以求生存，因此環保方面的投資已成為企業投資決策的一個重要的部份。
　　本研究之目的在探討公司環保資本支出與公司特徵之間的關聯性，以瞭解哪些因素會影響公司對於環保資本支出的決定，以期在管制機構制訂法令、企業從事環保資本支出決策及投資者預測企業環保資本支出時有所貢獻。
　　本研究認為影響公司環保資本支出的因素有八個：1、公司規模，2、資本密集度，3、總資產報酬率，4、內部現金流量，5、負債比例，6、違反環保法規所導致的罰款賠償金額，7、是否涉及公害糾紛，8、產業別。本研究以防治污染設備的投資金額與預計環保資本支出金額為替代變數，衡量公司實際的環保資本支出金額，分別探討其與公司特徵之間的關係。
　　本研究以民國81至85年曾經上市的製造業公司為對象，經實證結果，獲致以下的結論：
　　1、投資當年度的資本密集度與總資產報酬率、投資前一年度的內部現金流量，以及產業別等因素會影響公司當年度防治污染設備的投資金額，其餘的變數則不具解釋力。
　　2、資本密集度、內部現金流量、罰款賠償金額，以及產業別等因素可解釋預計未來年度的環保資本支出金額，而「公司規模」與預計環保資本支出金額呈反向的顯著關係，此與預期的方向不一致。

　　Environmental protection issues are becoming more and more important for company management all over the world. The pressures from government, society and international competition make firms invest more actively in environmental protection equipments. Nowadays environment-related investments have become an imperative part of a firm's investment decisions.
　　The purpose of this study is to (1) examine the relationship between the environmental capital expenditures and the firms' characteristics and (2) test how differences in the firms' characteristics affect environmental capital expenditures. The results of this study are expected to help the regulators make and modify environmental laws, (2) business managers make decisions about environmental capital expenditures, and (3) investors forecast firms' environmental capital expenditures.
　　In this study, we tested the following eight firms' characteristics for their relationship with environmental capital expenditures: environmental dispute, firm size, capital intensity, return on assets, internal cash flow, penalty and indemnity from violating environmental laws, and industry. We also used the amounts invested in pollution control equipments and the projected environmental capital expenditures to substitute firm's real environmental capital expenditures.
　　The data analyzed included Taiwan Stock Exchange listed manufacturing firms during 1992-1196. The empirical results showed that:
　　1.A firm's capital intensity and return on assets of the current year, internal cash flow of the previous year, and industry would affect the amount it invested in pollution control equipments of the current year.
　　2.A firm's capital intensity, internal cash flow, penalty and indemnity, and industry are significant variables in predicting its projected environmental capital expenditures for the next year.